微流光反应技术制备树脂状维生素D_3

合成维生素D_3的关键步骤是7-去氢胆固醇光照开环合成预维生素D_3,目前合成是在釜式光反应器中进行,原料转化率低,产物提纯难度大,产品生产周期长。本文利用微流光反应技术开展预维生素D_3的制备研究,与传统釜式光反应器相比,原料转化率从低于30%提高到95%,光照产物无需纯化,可直接通过热异构化反应制备树脂状维生素D_3,生产周期大为缩短。

Preparation of Resin-like Vitamin D3 by Micro-flow Photoreaction

The key process in the synthesis of vitamin D3 is the photochemical conversion from 7-dehydrocholesterol to pre-vitamin D3,which is currently carried out in batch photoreactors and suffers from low conversion efficiency,recycle of unreacted 7-dehydrocholesterol,and long production period.Using micro-flow photoreactor instead of batch photoreactor,the conversion yield of 7-dehydrocholesterol may be increased from less than 30％ to over 95％,allowing the photoreaction product to be directly used to prepare resin-like vitamin D3 through a thermal isomerization reaction and shortening the production period greatly.